This is a question asked by one of my readers. To answer this, we start from the first principles.
Knitting is a process of fabric forming by the intermeshing of loops of yarn. When one loop is drawn through another, loopstitch is formed.
Weft knitting is a method of forming a fabric in which the loops are made in horizontal way from a single yarn and intermeshing of loops take place in a circular or flat form or acrosswise basis.
Single Jersey is a weft knitted fabric produced with one set of needles is called single Jersey or plain knitted fabric.
GSM can be controlled either by taking a coarse count of yarn. Or for the same count of yarn increasing the stitches per inch. Stitch per inches can be increased by either resorting to a higher gauge machine or by decreasing the loop length.
In modern weft knitting machine there is a positive feeder called IRO which regulates the speed of the fed yarn. If the speed of IRO increases, the quantity of yarn passing in the m/c increases, so the loop size increases and hence the GSM decreases. If the speed decreases the reverse happens and the GSM increases.
The loop size can also be decreased by adjusting the distance between the cylinder and the dial needles: If the distance is more the loop size increases and hence the GSM decreases.
To get a first lesson on knitting please revert to this chapter.
As a bonus let us watch this song in which close to 720 intarsia knit fabrics are used:
